Ava Gene's, a Roman-inspired restaurant in Portland, Ore., incorporates colatura, a modern descendant of ancient Roman fish sauce, into several of its dishes. Deena Prichep/NPR hide caption

itoggle caption Deena Prichep/NPR

The moon is one of the most obvious natural indicators that the passing of time follows a pattern and can be tracked in a useful way. Bill McKelvie/iStockphoto.com hide caption

itoggle caption Bill McKelvie/iStockphoto.com